/**
 * @author wang'ji'cheng
 * @date 2025/7/19
 */
public class StringDemo {
    public static void main(String[] args) {

        String str1 = "aaa";
        String str2 = "bbb";
        String str3 = "ccc";
        String str4 = "ddd";

        StringBuilder sb = new StringBuilder();
        sb.append(str1);
        sb.append(str2);
        sb.append(str3);
        sb.append(str4);
        String sbString = sb.toString();
        System.out.println(sbString);
        System.out.println("=====================");
        String reSbString = sb.reverse().toString();
        System.out.println(reSbString);
        System.out.println("=====================");

        System.out.println(sb.length());
        System.out.println("打印StringBuilder=================");
        System.out.println(sb);
    }

}
